This aim of this research is to gain a better understanding of factors that relate to the increased health and effective functioning of older adults. Specifically, efficiency of psychomotor performance declines with advancing age leading to profound effects on older adults' quality of life. For this reason, researchers have focused on the influence that individual lifestyle habits have on the aging process. One lifestyle choice that has been found to positively contribute to the efficiency of older adults' psychomotor performance is cardiovascular exercise. This relationship appears to be especially significant when older adults are challenged with more complex or effortful tasks. Two lines of research are relevant here. First, age-related discrepancies have been documented using tasks that require executive control processes that are subserved by the frontal lobes. These differences are not consistently observed using tasks that are not subserved by the frontal lobes, leading investigators to believe that aging has a specific, rather than generalized, impact on cognitive functioning. Secondly, prolonged participation in cardiovascular exercise has been found to maintain the cognitive functioning critical for healthy aging. Therefore, the purpose of this research is to examine the role of a 6-month cardiovascular exercise intervention trial on electrocortical (ERPs) and behavioral measures (RT) of executive control processes. In addition, a non-cardiovascular exercise control group that participates in a 6-month stretching and toning program will be used for comparison. Participants will be measured before and after exercise training during engagement in several tasks designed to elicit different executive functions (e.g., interference control, task switching, inhibition). Each task also contains a non-executive condition that will be used for comparison to examine the specificity of exercise participation of cognitive functioning. A secondary aim of this project is to determine the effects of an acute bout of exercise on cognitive functioning. Both groups will participate in several bouts of exercise followed by immediate measurement on the tasks outlined above to determine whether acute exercise has beneficial effects on executive control processes. The significance of this research may include the increased understanding of factors related to the amelioration of age-related decrements in central nervous system functioning and recommendations for the maintenance of cognitive health during the later stages of life. [unreadable] [unreadable]